import { app, BrowserWindow, ipcMain, session } from 'electron';
import path from 'path';
import fs from 'fs';
import https from 'https';

const AUTH_HOST = 'https://account.rokojori.com';
const PORT = 3000;

function tokenFile(): string {
  return path.join( app.getPath( 'userData' ), 'tokens.json' );
}

interface Tokens {
  accessToken: string;
  refreshToken: string;
}

function loadTokens(): Tokens | null {
  try {
    const raw = fs.readFileSync( tokenFile(), 'utf-8' );
    return JSON.parse( raw ) as Tokens;
  } catch {
    return null;
  }
}

function saveTokens( tokens: Tokens ): void {
  fs.writeFileSync( tokenFile(), JSON.stringify( tokens ), 'utf-8' );
}

function clearTokens(): void {
  try { fs.unlinkSync( tokenFile() ); } catch { /* already gone */ }
}

function postJson( url: string, body: unknown ): Promise<unknown> {
  return new Promise( ( resolve, reject ) => {
    const data = JSON.stringify( body );
    const parsed = new URL( url );
    const req = https.request(
      {
        hostname: parsed.hostname,
        path: parsed.pathname,
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Content-Length': Buffer.byteLength( data ),
        },
      },
      ( res ) => {
        let raw = '';
        res.on( 'data', ( chunk: string ) => { raw += chunk; } );
        res.on( 'end', () => {
          try { resolve( JSON.parse( raw ) ); }
          catch { reject( new Error( `Non-JSON response: ${raw}` ) ); }
        } );
      }
    );
    req.on( 'error', reject );
    req.write( data );
    req.end();
  } );
}

function registerHeaderInjector( getToken: () => string | null ): void {
  session.defaultSession.webRequest.onBeforeSendHeaders(
    { urls: [ `http://localhost:${PORT}/*` ] },
    ( details, callback ) => {
      const token = getToken();
      const headers = { ...details.requestHeaders };
      if ( token ) headers[ 'Authorization' ] = `Bearer ${token}`;
      callback( { requestHeaders: headers } );
    }
  );
}

let mainWindow: BrowserWindow | null = null;
let loginWindow: BrowserWindow | null = null;
let currentTokens: Tokens | null = null;

function createLoginWindow(): void {
  loginWindow = new BrowserWindow( {
    width: 420,
    height: 520,
    resizable: false,
    webPreferences: {
      nodeIntegration: false,
      contextIsolation: true,
      preload: path.join( __dirname, 'preload.js' ),
    },
    title: 'Roject — Sign in',
  } );

  loginWindow.loadFile( path.join( __dirname, 'login.html' ) );
  loginWindow.on( 'closed', () => { loginWindow = null; } );
}

function createMainWindow(): void {
  mainWindow = new BrowserWindow( {
    width: 1400,
    height: 900,
    webPreferences: {
      nodeIntegration: false,
      contextIsolation: true,
    },
    title: 'Roject',
  } );

  mainWindow.loadURL( `http://localhost:${PORT}/` );

  const localBase = `http://localhost:${PORT}/`;

  // Keep the main window on localhost — any navigation away means the user needs to re-auth
  mainWindow.webContents.on( 'will-navigate', ( event, url ) => {
    if ( !url.startsWith( localBase ) ) {
      event.preventDefault();
      clearTokens();
      currentTokens = null;
      mainWindow?.close();
      createLoginWindow();
    }
  } );

  mainWindow.on( 'closed', () => { mainWindow = null; } );
}

function loadEnv(): void {
  const envPath = path.join( __dirname, '..', '..', '.env' );
  try {
    const lines = fs.readFileSync( envPath, 'utf-8' ).split( /\r?\n/ );
    for ( const line of lines ) {
      const trimmed = line.trim();
      if ( !trimmed || trimmed.startsWith( '#' ) ) continue;
      const eq = trimmed.indexOf( '=' );
      if ( eq === -1 ) continue;
      const key = trimmed.slice( 0, eq ).trim();
      const val = trimmed.slice( eq + 1 ).trim().replace( /^["']|["']$/g, '' );
      if ( key && !( key in process.env ) ) process.env[ key ] = val;
    }
  } catch { /* no .env file — rely on inherited env */ }
}

function startExpressServer(): void {
  loadEnv();
  // Tell the server where the project root is so __dirname-relative paths work when compiled.
  // build/electron/ → up two levels → project root.
  process.env.ROJECT_ROOT = path.join( __dirname, '..', '..' );
  const serverPath = path.join( __dirname, '..', 'server', 'server', 'index.js' );
  // eslint-disable-next-line @typescript-eslint/no-require-imports
  const { startServer } = require( serverPath ) as { startServer: ( port: number ) => void };
  startServer( PORT );
}

app.whenReady().then( () => {
  registerHeaderInjector( () => currentTokens?.accessToken ?? null );

  ipcMain.handle( 'auth:login', async ( _event, email: string, password: string ) => {
    try {
      const result = await postJson( `${AUTH_HOST}/api/auth/login`, { email, password } ) as Record<string, unknown>;
      if ( result.accessToken && result.refreshToken ) {
        currentTokens = { accessToken: result.accessToken as string, refreshToken: result.refreshToken as string };
        saveTokens( currentTokens );
        return { ok: true };
      }
      return { ok: false, error: ( result.error as string ) ?? 'Login failed' };
    } catch ( err ) {
      return { ok: false, error: String( err ) };
    }
  } );

  ipcMain.on( 'auth:login-success', () => {
    loginWindow?.close();
    createMainWindow();
  } );

  startExpressServer();

  // Give the server a moment to bind before loading the window
  setTimeout( () => {
    currentTokens = loadTokens();
    if ( currentTokens ) {
      createMainWindow();
    } else {
      createLoginWindow();
    }
  }, 500 );

  app.on( 'activate', () => {
    if ( BrowserWindow.getAllWindows().length === 0 ) {
      if ( currentTokens ) createMainWindow();
      else createLoginWindow();
    }
  } );
} );

app.on( 'window-all-closed', () => {
  if ( process.platform !== 'darwin' ) app.quit();
} );